Surgical retractor and method of use

ABSTRACT

The present invention relates to a surgical retractor that immobilizes tissue at a surgical site. A preferred embodiment of the retractor is used during minimally invasive direct coronary bypass procedures to arrest movement of the grafting site while the heart continues pumping. Tape or thread can be used to connect the artery to the retractor with a holder.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 09/307,195filed on May 7, 1999 (pending) which is a continuation application ofInternational Application No. PCT/US98/08348, filed on Apr. 24, 1998 anddesignating the United States which is acontinuation-in-part applicationof U.S. Ser. No. the entire teachings of the above applications beingincorporated herein by reference.

BACKGROUND OF THE INVENTION

Numerous devices have been used to position tissue at a surgical site toaid in the performing of surgical procedures. Retractors, for example,have been used to hold an artery in position during operations adjacentto the heart to prevent movement of the artery. This serves to minimizethe risk of injury to the artery and adjacent tissue and can facilitatethe desired anastomosis.

A recently developed procedure, referred to as the minimally invasivedirect coronary artery bypass procedure, has been used to graft onto acoronary artery without cardiopulmonary bypass. This procedure involvesthe grafting of the left internal mammary artery (LIMA) onto the leftanterior descending (LAD) or other artery. As this procedure does notrequire the use of a heart lung machine to oxygenate and pump blood, themorbidity and mortality associated with this procedure is substantiallylower than previous bypass techniques. A problem associated with theminimally invasive procedure, however, is that while the heart continuesto pump during the procedure, the motion of the heart can interfere withthe surgeon's task of attaching the LIMA to the LAD. There is also aneed to stop blood flow in the area of the graft to maintain a clearfield of view and provide precise suture placement.

Two basic strategies have been employed to address the problem ofoperating on a moving site, one being the use of pharmacological agentsto limit heart motion, and the other being mechanical, such as a twoprong retractor that is pushed down against the heart on both sides ofthe artery, or alternatively, upward traction away from the moving heartby traction tape or suture thread. Both of these options, however, haveproblems associated with them. Both options are susceptible to somemovement of the vessel grafting site. The use of pharmacological agentsis undesirable and impairs circulatory function. Traction by compressionof the heart against the spine does serve to immobilize the site but cancompromise the ability of the heart to maintain circulation and resultin hypotension. Upward traction can involve circumferential compressionof the artery to occlude the artery and prevent blood flow, howeverupward traction that is sufficient to immobilize the site can causeinjury, stenosis or occlusion of the vessel.

There is a continuing need however for improvement in devices andmethods for retaining tissue at surgical sites to further reduce therisks associated with surgical procedures where the devices and methodsare inexpensive, safe and reliable.

SUMMARY OF THE INVENTION

The present invention relates to a surgical retractor for immobilizingtissue at a surgical site and to a method of using the retractor duringa surgical procedure. A preferred embodiment of the retractor includes aretaining element having an aperture that exposes the surgical site anda holder that is used to position tissue at the surgical site relativeto the retaining element. A handle can be attached to or fabricated withthe retaining element or platform so that the user can manipulate theposition of the retractor as needed.

In a preferred embodiment of the invention a connector such as elastictape or thread is used to position tissue at the surgical site withinthe retractor aperture and to prevent movement of the tissue during theprocedure. The connecting cord, thread or tape also aids in thecompression of the artery in a grafting procedure to occlude flow on oneor both sides of the surgical site. The cord is attached to the holderon the retaining element. A preferred embodiment of the holder can be aplurality of slits or openings positioned on both sides of the retractorthat receive and frictionally secure the cord on both sides of theaperture. In another preferred embodiment a mechanical fastener is usedto grip both sides of the cord. The fastener can be a spring mountedvalve, for example, that allows the user to adjust the tension in thecord.

A preferred embodiment of the invention comprises a retaining element orbase having two sections that can be separated after the procedure iscomplete to permit removal of the retractor from under the graftedartery. Another preferred embodiment uses a side opening in the platformof the retractor that extends to the aperture so that the grafted arteryslips through the side opening during removal. During minimally invasivedirect coronary artery bypass operations, one or more surface sectionsof the retractor platform can be positioned against the inner surface orposterior aspect of one or both ribs adjacent to the surgical site.Thus, the size and geometry of the platform are selected to utilize theadjoining ribs where the upper surface of the platform frictionallyengages the inner surface of one or more ribs to hold the retractor in afixed position. The retractor can be beneficial in any procedure whereit is necessary to stabilize a surgical site. For example, the retractorcan also be used for grafting onto the diagonal, right or other coronaryarteries without altering the heart's pumping function.

The coronary arteries are about 1-2 mm in diameter, and the pumpingheart can move these arteries over distances of several millimetersduring each heartbeat. As the movement of even 1 or 2 millimeters canresult in a displacement of the grafting site that can substantiallyinterfere with effective anastomosis, it is desirable to restrainmovement of the artery at the surgical site in any direction to lessthan 1 mm. The retractor of the present invention restrains movement inthe plane of the base to less than 0.5 mm, and preferably less than 0.2mm.

In a preferred embodiment of the invention, the handle or articulatingarm that is secured to the platform can be held in position by the user,attached to a frame that is fixed around the operative site or simplyclipped to a drape around the site.

In a preferred embodiment of the invention, the surgical retractor canbe optically transmissive or transparent to allow enhanced visibility ofthe underlying adjacent tissue at the desired surgical site. Theaperture of the retractor in accordance with the present invention,varies in size and can range from 1-3 cm in length and 5-15 mm in width.

In a preferred embodiment, the surgical retractor has raised holderelements disposed in the longitudinal dimension of the retractor, eachholder element having a pair of slots that frictionally grip an end of aconnector such as an elastic tape or thread which extends through theaperture to attach tissue to the retractor. The surgical retractorfurther has run off areas on the four coners of the retractor that havea downward slope. These run off areas allow for fluid drainage duringthe surgical procedure to assist in maintaining the surgical fieldadjacent to the aperture clear of blood during the anastomosis. The fourconers of the base have a gradually thinner cross-section to provide thedownward slope.

In a preferred embodiment, the surgical retractor includes atwo-component configuration to allow the retractor to be separated afterthe surgical procedure is completed to permit removal of the retractorfrom under the grafted artery. A pair of plastic tabs extend between thetwo components to securely retain the components together during theprocedure and to allow the surgeon to release the components followingthe procedure by cutting the tabs with a knife.

In another preferred embodiment, the surgical retractor has slots orgrooves on the bottom surface of the retractor to allow the user toplace the connector such as elastic tape or thread, either under or overthe retractor to position tissue at the surgical site within theretractor aperture and to prevent movement of the tissue during theprocedure. When these slots are used the tapes are threaded through thetissue of the heart-wall of the patient and then aligned to bepositioned in the desired underlying slots. The surgeon can includeadditional tissue around the blood vessel as the tapes are tightened sothat the blood vessel is compressed by the adjacent tissue rather thanbeing constricted by the tapes. Additionally, the surgeon can positionthe tapes at a relatively sharp angle of approach. Alternately, a widerangle of approach may be used wherein the tapes are threaded around theouter surface of the retractor so that more tissue is positioned betweenthe tapes and the blood vessel. The route used by the surgeon variesdepending on the depth of the desired blood vessel and the surgeon'spreferred approach to performing the anastomosis.

In a preferred embodiment, portions of the bottom surface form aslightly curved surface which extends a slight distance downwardlyparallel to the lengthwise dimension of the aperture which assists inretaining the retractor in the desired position on the heart wall of thepatient as it continues beating. The bottom surface that surrounds theartery and is in contact with the pericardium can be roughened orabraded to frictionally engage the pericardium around the artery andthereby locally restrict heart motion around the surgical site. Thereare elevated regions or protrusions such as ridges or nubs, for example,disposed on the bottom surface of the retractor to frictionally engagethe pericardium wall around the surgical site.

When used in a minimally invasive coronary bypass procedure, theretractor is positioned to expose the left anterior descending (LAD)artery grafting site after incision, removal of the rib section anddissection of the left internal mammary artery (LIMA) from the chestwall. A pair of cords, for example, silastic tape (i.e. a siliconelastomer) or suture thread, are passed through the myocardium at twolocations flanking the artery grafting site with blunt needles. The fourends of the two cords are connected to the platform holder withsufficient tension to occlude blood flow on both sides of the operativesite. The tapes compress the artery against the bottom surface of theplatform while they hold the artery grafting site in a fixed positionrelative to the aperture. The coronary artery is opened longitudinallyand the end of the mammary artery is sewn to the graft opening withmultiple fine sutures. The cords are released, blood flow is restoredand the anastomosis is inspected for hemostatis and other defects andthe wound is closed.

The platform can include tabs or cord retainers that extend into theaperture to provide a surface against which the arteries can becompressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a surgical retractor in accordance witha preferred embodiment of the invention.

FIG. 2 is a perspective view of a surgical site illustrating a surgicalprocedure.

FIG. 3 is a perspective view of a surgical retractor for a graftingprocedure in accordance with the invention.

FIG. 4 is a bottom perspective view of a surgical retractor inaccordance with the invention.

FIG. 5 is a cross-sectional view of a surgical retractor during asurgical procedure.

FIGS. 6A and 6B are partial cross-sectional views of a holder inaccordance with the invention.

FIG. 7 is a top view of a two piece retainer in accordance with theinvention.

FIG. 8 is a top perspective view of another preferred embodiment of asurgical retractor in accordance with the invention.

FIG. 9 is a top perspective view of another preferred embodiment of asurgical retractor in accordance with the invention.

FIG. 10 is a schematic diagram illustrating a surgical procedure inaccordance with the invention.

FIG. 11 is a perspective view of a frame supporting a retractor inaccordance with the invention.

FIGS. 12A and 12B are enlarged detailed views of a surgical retractor inaccordance with the invention.

FIG. 13 is an enlarged detailed top view of the preferred embodiment ofa surgical retractor illustrating a separated two-section configurationof the retractor.

FIG. 14 is an enlarged detailed top view of the preferred embodiment ofthe surgical retractor shown in FIG. 13.

FIG. 15 is an enlarged detailed bottom view of the preferred embodimentof the surgical retractor shown in FIG. 13.

FIG. 16 is a perspective view of a preferred embodiment of a surgicalretractor in a surgical site illustrating a surgical procedure inaccordance with the present invention.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of the invention is illustrated in connectionwith FIG. 1. A retractor 10 includes a retaining element or base 12having an aperture 16 that is positioned to expose tissue at a surgicalsite. The base 12 can be made with a metal or a molded plastic material.The retractor 10 can be sterilized after each use, or alternatively, canbe disposable after one procedure. A handle 30 or articulating arm canbe permanently attached to the base 12, or as described below inconnection with other preferred embodiments, can be detachable.

A suction tube 32 can be attached to the handle 30 or integrated thereinand is used to remove material such as blood from the operative site. Inthis particular embodiment the tube 32 is connected at one end to a tube34 from a suction pump and connected at a second end to a port 36 influid communication with a channel within tube 28 that extends aroundthe periphery of base 12. The peripheral tube can have small openings 38positioned on the sides or top thereof through which fluid such as bloodor other debris can be suctioned from the surgical site to maintain aclear field.

A preferred embodiment of the invention can be used at a surgical site50 such as the example illustrated in FIG. 2. In this particularprocedure for a coronary graft without cardiopulmonary bypass, a sectionof the 4th costal cartilage or rib 56 is removed to expose a section ofthe LAD artery 61.

A proximal portion of the LIMA 62 is dissected from the chest wall toexpose an end 65 to be grafted onto a grafting site 60 on artery 61.Blood flow in vessel 62 can be occluded with a clamp 64.

In this example, a connector such as a pair of cords or silastic tapes70, 72 are threaded through myocardium surface 78 under the artery 61 attwo locations 74, 76 on opposite sides of the grafting site 60. Notethat the exposed surface 78 of heart 52 is undergoing substantialmovement during the procedure.

As seen in the reverse perspective view of FIG. 3 in which the retractor10 has been inserted and positioned during the procedure, the retractor10 serves to immobilize the grafting site 60 using connecting tapes 70,72 which are stretched and attached to a holder mechanism includingslots 20 a-20 d in the peripheral edge of base 12. As described ingreater detail below, the slots 20 A-20 d can be manually opened orclosed using actuators 22 a-22 d, respectively, to allow the user toadjust the tension in the tapes or threads.

The aperture 16 extends longitudinally along the axis of artery 61. Thesite 60 is preferably located in the plane of the upper surface of base12. The tapes 70, 72 exert a compressive force on the artery 61 which ispressed against a bottom surface 40 as seen in FIG. 4. Moreparticularly, the tapes 70, 72 extend in a direction that issubstantially perpendicular to the artery 61 axis exposed in theaperture 16. The aperture can have a first pair of lateral sections 18 aand 18 b which are aligned to accommodate the positioning of tape 70 andthe aperture can also have a second pair of lateral sections 18 c and 18d to accommodate the positioning of tape 72. Alternatively, holesextending through the base 12 that are separated from the aperture canbe used. The holes are large enough to provide easy feed through and canbe angled towards the bottom center to provide compression of the arteryat lower tension of the cord.

The size of the aperture can be in the range of 1-3 cm in length and5-15 mm in width. The aperture can be narrower in the center and widerat the opposite ends to accommodate the openings or sections 18 a-18 d.

Between each pair of sections 18 a-18 d and 18 a-18 d, a sidewallsection of the aperture, namely tabs 24, 26 extend on opposite ends ofaperture 16. The tapes 70, 72 compress respective portions of artery 61on opposite sides of site 60 against tabs 26, 24. As seen in FIG. 4,those portions 42, 44 of the bottom surface 40 are in contact withartery 61 and compress it. The bottom surface that surrounds the arteryand is in contact with the heart wall can be roughened or abraded tofrictionally engage the heart wall around the artery and thereby locallyrestrict heart motion around the surgical site.

In a preferred embodiment of the invention opposite ends 82 and 84 canbe positioned under adjacent ribs 54 and 58, respectively. Thiseliminates any substantial movement of the base 12 while the heart ispumping so that anastomosis 80 of the end 65 onto site 60 can be quicklycompleted. The opposite ends 82, 84 can be slightly raised relative tothe plane of the remainder of the base 12 to provide a concave structureto enhance the frictional engagement of sections 82, 84 to ribs 54, 58,respectively. The platform has a substantially rectangular shape witheach side having a length in the range between 3.5 cm and 6 cm. Thus thesurface area of the platform is between 12 cm² and 25 cm², preferablybetween 14 cm² and 20 cm². This size fits readily in the incisionbetween the ribs and can be positioned with both ends extending underthe 3rd and 5th ribs. This structure exerts little downward force on theheart or upward force on the artery while immobilizing the artery at thesurgical site. Also the anterior-posterior compression of the arteryavoids trauma to the artery due to circumferential compression. Byengaging the ribs, the retractor is self retaining providing for easieruse and manipulation.

As seen in FIG. 5, the tape 76 under the bottom surface 94 of the tab 24lifts the artery 60 to form an occlusion 86. This view also shows theoptional channel 92 extending around the periphery of base 12 that isused to irrigate or suction around the site.

The fastening mechanism is illustrated in the partial cross-sectionalviews of FIGS. 6A and 6B. The closed position 10 is illustrated in FIG.6A where spring 112 has expanded to move slot 116 in element 115 out ofalignment with slot 114 in the outer tube. The cord 72 is displaced andfrictionally grasped by the sliding movement of element 115. The usercan manually displace 118 to align slot 114 with slot 116 whilecompressing spring 112. In the “open” position 120, the cord 72 can beeasily removed or pulled through to increase tension.

After the procedure is complete the retractor 10 needs to be removedfrom the site. In the embodiment of FIG. 1, the base 12 can be formedwith two sections or plates 14 a, 14 b. As seen in FIG. 7, thesecomponents can be separated at joint 25 to allow removal of theretractor 10. The two halves 14 a, 14 b can be connected with africtional tube section 96.

In the preferred embodiment illustrated in FIG. 8, the retractor 100 canhave a plurality of handle attachment sites 102, 104, 106, 108 so thatthe user can attach the handle 105 at any site to provide the mostconvenient access to the aperture and facilitate immobilization of otherarteries. The handle can alternatively be positioned between the twocords at an orthogonal angle relative to the aperture axis and extendingabove the top surface of the base.

In another preferred embodiment of the invention illustrated in theperspective view of FIG. 9, a retractor 140 has a handle 142, slots 144located in the plane of the aperture 160 to secure the cords, endsections 162, 164 that engage the ribs 54, 58, tabs 148, 150 forcompression of both sides of the artery at the site 60 and a sideopening 146 so that the retractor can be removed.

In this embodiment, the LIMA slides out through opening 146 duringremoval of the retractor after completion of the procedure. This unitaryretractor structure 140 can also include various features describedpreviously in connection with the embodiment of FIG. 1 including theattached or integrated suction tube, the detachable handle, theirrigation or suction channel with ports or the mechanically actuatedfasteners.

A preferred method of stabilizing tissue during a coronary bypassprocedure 200 is illustrated in the process flow sequence of FIG. 10. A5-8 cm sized incision is made over the 4th rib and a section of the 4thcostal cartilage is removed 202. The LIMA is dissected from the chestwall 204 and divided distally. After blood flow assessment the LIMA canbe temporarily closed with a spring loaded clip.

A self-retaining wound retractor is used to distract the edges of theincision and a “trap door” incision is made in the pericardium and thecut edge sewn to the skin to pull the pericardial sack and heartanteriorly. The LAD is exposed and a site suitable for anastomosis isselected for grafting 206. Tapes are inserted in the myocardium withblunt needles approximately 1-2 cm apart 208 and the retractor isinserted 210 with the tapes being pulled through the aperture andpositioned in the lateral sections thereof. The tapes are connected tothe holder 212 to compress the artery 214 and occlude blood flow on bothsides of the grafting site. The tension in the tapes can optionally beadjusted during the procedure to minimize blood loss at the site.

The retractor is secured 216 at the site by positioning one or both endsunder adjoining ribs, or alternatively, attaching the handle or arm tothe wound retractor or other implement. The grafting site undergoes lessthan 0.1 mm of movement in any direction during this example procedure.

The site is suctioned or irrigated 218 during anastomosis, the graftingsite is inspected, the tapes are released from the holders, and theretractor is removed either by sliding the LIMA through a side openingin the retractor or detaching a section of the retractor to accommodateremoval of the LIMA from the aperture. After blood flow is restored, thesite is inspected and closed 220.

Although the use of the retractor has been described in connection witha particular bypass procedure, it can also be used in other proceduressuch as bypass operations involving the diagonal, right or othercoronary artery where movement at the site can interfere with theprocedure.

Alternative embodiments involve opening of the chest and positioning theretractor at any exposed site on the heart wall or surrounding areas toimmobilize the operative site. The retractor serves to isolate the siteand limits or stops motion at the site due to respiratory movement ofthe lungs or the pumping motion of the heart.

In another preferred embodiment, a stabilizer system or frame 240manufactured by Genzyme Surgical Products is illustrated in FIG. 11 tosupport a surgical retractor 260 in accordance with the invention.

The frame 240 used with the invention includes a bar 242 having an arm244 extending orthogonally from a first end and attached to a second arm246 with a thumb screw at a second end. Each arm 244, 246 has a pair ofmounting elements 252, 255 on which a pivot rod 256 can be mounted. Thisrod 256 can be rotated 360 degrees to any desired position such thatmounting arm 245 can oriented relative to the surgical site as needed toposition the retractor 260. Each arm 244, 246 has a pair of grippers248, 250 that engage anatomical features such as neighboring ribs at thesite to stabilize the frame 240.

The mounting arm 245 supports the handle or support arm 262 with afriction fitting 258 which the user tightens with knob 268 to grip arm262 at region 266. The support arm 262 has a knob 264 at one end thatcan be turned by the user to engage a post 276 shown in FIG. 12A. A ballon the post 276 can be slipped through an opening 265 in the second endof arm 262 and locked into position using knob 264.

The post 276 can be pivoted relative to arm 262 by loosening the knob264, thus allowing the user to orient the retractor 260 at the site forfine positioning. The post 276 is mounted on a plastic retaining element270 in this embodiment. The element 270 can be a transparent or opaquemolded device that can be separated into two components 272, 274 asdescribed previously. The two components can be attached by friction fitrods 294 that are inserted into holes in element 272. Element 270 can bemade with a transparent material to enhance visibility at the site.

Both components have raised holder elements 284, 286. Element 284 has apair of slots 288, 289 that each frictionally grip an end of a cordwhich extends through the aperture 278 to attach tissue to theretractor. The second end of each cord is gripped by corresponding slots290, 292 in element 286.

Tabs or cord retainers 280, 282 are integrally formed with component 274and function as described previously. In the detailed partial view ofFIG. 12B, the front inclined surface can be formed at a shallower anglesuch that the top ridge 279 is narrower. This embodiment of cordretainer 281 affords easier insertion of cords into the aperture.

This embodiment can also be formed with integral suction channels oropenings in the top surface of the element 270. A suction tube can beattached through or with the arm 262 or attached to a suction port onelement 270.

FIG. 13 illustrates an enlarged detailed top view of a preferredembodiment of the surgical retractor. A retractor 300 includes aretaining element or base 312 having an aperture 316 that is positionedto expose tissue at a surgical site. The base 312 can be made with metalor a molded plastic material. The retractor can be used on multiplevessels for the same patient, can be sterilized and reused on additionalpatients as desired, or can be disposed of after each use.

The size of the aperture 316 can be in the range of 1-3 cm in length and5-15 mm in width. The aperture 316 can be narrower in the center andwider at the opposite ends to accommodate the opening required for thesurgical site. The aperture 316 can have a first pair of lateralsections 320 a and 320 b which are aligned to accommodate thepositioning of a first connector such as tape or thread and the aperturecan also have a second pair of lateral sections 320 c and 320 d toaccommodate the positioning of a second connector such as tape orthread. A connector such as a pair of cords or silastic tapes arethreaded through myocardium surface under an artery at two locations onopposite sides of the grafting site.

Between each pair of sections 320 a-320 b and 320 c and 320 d, asidewall section of the aperture, namely tabs 322, 324 extend onopposite ends of aperture 316. The aperture can also have longitudinallyextending angled sidewalls 325 a, 325 b, that descend at an obliqueangle into the aperture. The angled sidewalls 325 a, 325 b, as well asthe angled upper surfaces of tabs 322, 324 aid in providing betteraccess to the surgical site. The oblique angle extends from the plane ofthe upper surface containing surface regions 327 a, 327 b to thesurfaces of sidewalls 325 a, 325 b. The tapes extend through the hearttissue adjacent to the artery and compress respective portions of anartery on opposite sides of site 60 against tabs 322, 324 as the tapesare tightened by the surgeon.

The surgical retractor has raised holder or sidewall elements 326, 328.Element 326 has a pair of slots 330, 332 that each frictionally grip anend of a cord which extends through the aperture 316 to attach tissue tothe retractor. The second end of each cord is gripped by correspondingslots 334, 336 in element 328.

There are run off areas 338 a-338 d on the coners of the retractor thathave a downward slope. These run off areas allow for fluid drainageduring the surgical procedure to assist in maintaining the surgicalfield adjacent to the aperture 316 clear of blood during theanastomosis. The four coners of the base 312 have a gradually thinnercross-section to provide the downward slope. The top surface of the base312 can have two substantially planar areas 327 a, 327 b which extendbetween the angled sidewalls 325 a, 325 b and the corresponding holderelements 326, 328 which extend in a direction orthogonal to the plane ofthe upper surface of base 312. Additionally the upper surface of base312 has end walls 329 a, 329 b, 329 c, 329 d at both ends of theaperture. The end walls 329 a-d combined with raised sidewall elements326, 328 define the openings 338 a-d.

A post 340 is used with the frame 240 shown in FIG. 11 to allow the userto orient the retractor 300 at the site for fine positioning. The post340 is mounted on the plastic retaining element 342 in this embodiment.Element 342 can be made with a transparent material to enhancevisibility of the underlying adjacent tissue at the desired surgicalsite or can be an opaque molded device. The element 342 can be separatedinto two components 344, 346. The two components 344, 346 can beattached by fit rods 348, or similar retaining mechanisms, that areinserted into holes in element 346. In a preferred embodiment of thisinvention, a pair of plastic tabs 347 or bridge-type members extendbetween the two components, 344 and 346. The plastic tabs 347 can bewelded or snapped into place to securely retain the components togetherduring the procedure and to allow the surgeon to release the componentsfollowing the procedure by cutting the tabs 347 with a knife.

FIG. 14 illustrates an enlarged detailed top view of the surgicalretractor 300 showing the combined two-component 344, 346 configuration.The two-component 344, 346 configuration of the preferred embodiment ofthe surgical retractor allows the retractor to be separated after thesurgical procedure is completed to permit removal of the retractor 300from under the grafted artery.

FIG. 15 illustrates an enlarged detailed view of the bottom surface 360of the preferred embodiment of the surgical retractor 300. The portions362, 364 of the bottom surface 360 are in contact with an artery andform a slightly curved surface which extends a slight distancedownwardly parallel to the lengthwise dimension of the aperture 316. Theaddition of the curved bottom surface 360 in combination with theelevated regions 366, described below, further assist in retaining theretractor in the desired position on the heart wall of the patient as itcontinues beating. The bottom surface 360 that surrounds the artery andis in contact with the pericardium can be roughened or abraded tofrictionally engage the pericardium around the artery and therebylocally restrict heart motion around the surgical site. There areelevated regions 366 or protrusions such as ridges or nubs for example,disposed on the bottom surface 360 of the retractor to frictionallyengage the pericardium.

A preferred embodiment may have slots or grooves 368 a-368 d as shown inFIG. 15 on the bottom surface 360 of the retractor to allow the user toplace the tapes either under or over the retractor for subsequentsecurement. When these slots are used, the tapes are threaded throughthe tissue of the heart wall of the patient and then aligned to bepositioned in the desired underlying slots. The tapes are then graspedand lifted around the outer surface of the holder elements 326 and 328and then positioned in the desired slots 330, 332, 334, 336. Thisfeature allows the surgeon to include additional tissue around the bloodvessel as the tapes are tightened so that the blood vessel is compressedby the adjacent tissue rather than being constricted by the tapes.Additionally, this feature allows the surgeon to position the tapes at arelatively sharp angle of approach. The tapes are then threaded throughthe aperture and into the desired slots. Alternately, a wider angle ofapproach may be used wherein the tapes are threaded around the outersurface of the retractor so that more tissue may be positioned betweenthe tapes and the blood vessel. The route used by the surgeon will varydepending on the depth of the desired blood vessel and the surgeon'spreferred approach to performing the anastomosis.

FIG. 16 illustrates a transparent surgical retractor positioned in thesurgical site 380. The retractor 300 has been inserted and positionedduring a procedure for a coronary graft without a cardiopulmonarybypass, a section of the 4^(th) costal cartilage or rib 382 is removedto expose a section of the LAD artery 384. The retractor 300 serves toimmobilize the grafting site 386 and is preferably used in combinationwith the connecting tapes 388, 390 which are stretched and attached to aholder mechanism including slots 330, 332, 334, 336 in the peripheraledge of base 312.

The aperture 316 extends longitudinally along the axis of the artery384. The site 380 is preferably located in the plane of the uppersurface of base 312. The tapes 388, 390 exert a compressive force on theartery 384 which is pressed against the bottom surface 360 as seen inFIG. 15. More particularly, the tapes 388, 390 extend in a directionthat is substantially perpendicular to the artery 384 exposed in theaperture 316.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A surgical device for a coronary bypass procedure comprising; a stabilizer; a retaining element attached to the stabilizer having an aperture defining an operative site over an artery; and a holder on the retaining element, the holder positioned to receive a connector that extends underneath the artery such that the connector is frictionally attached to a slot in the holder and compresses the artery against a surface on the retaining element at a first arterial position on a first side of the operative site and at a second arterial position on a second side of the operative site.
 2. The surgical retractor of claim 1, wherein the aperture is sized to have a length that ranges from 1 to 3 cm and a width that ranges from 5 to 15 mm.
 3. The surgical retractor of claim 1, having a longitudinal dimension, further comprising raised sidewall elements disposed along the longitudinal dimension of the retractor.
 4. The surgical retractor of claim 3, wherein the raised sidewall elements have a plurality of slots to frictionally grip an end of the connector.
 5. The surgical retractor of claim 1, wherein the connector comprises flexible tape or thread.
 6. The surgical retractor of claim 1, wherein the retaining element comprises a first, a second, a third and a fourth corner, at least one corner has a base having a gradually thinner cross-section to provide a downward slope to allow for fluid drainage during the procedure.
 7. The surgical retractor of claim 1, wherein the retaining element has a bottom surface comprising a plurality of slots to allow for the placement of the connector under or over the retractor to position tissue at the surgical site within the retractor aperture.
 8. The surgical retractor of claim 1, wherein the retaining element has a bottom surface having portions that are curved and extend a distance downwardly parallel to a lengthwise dimension of the aperture to retain the retractor in a desired position.
 9. The surgical retractor of claim 1, wherein the retaining element comprises a plurality of separable sections.
 10. The surgical retractor of claim 9, wherein the separable sections comprise a plurality of tabs which extend between the separable sections.
 11. The surgical retractor of claim 1, wherein the retaining element is optically transmissive.
 12. A method of positioning an artery during surgery comprising the steps of: positioning a retaining element at a surgical site, the retaining element extending over an artery and having an aperture that exposes a portion of the artery at the surgical site; positioning a connector under a portion of the artery; and connecting the connector to the retaining element, the connector being frictionally attached to a slot on the retaining element, to occlude the artery at a first arterial position at a first side of the surgical site with the retaining element and occluding the artery at a second arterial position at a second side of the surgical site with the retaining element.
 13. The method of claim 12 further comprising sizing the aperture to have a length that ranges from 1 to 3 cm and a width that ranges from 5 to 15 mm.
 14. The method of claim 12 further comprising providing the retaining element having a longitudinal dimension comprising raised sidewall elements disposed along the longitudinal dimension.
 15. The method of claim 14 further comprising providing the raised sidewall elements having a plurality of slots to frictionally grip an end of the connector.
 16. The method of claim 12 further comprising providing the retaining element having a first, a second, a third and a fourth corner, at least one corner having a gradually thinner cross-section to provide a downward slope for fluid drainage during a procedure.
 17. The method of claim 12 further comprising providing the retaining element having a bottom surface comprising a plurality of slots to allow for the placement of the connector under or over the retractor to position tissue at the surgical site within the retractor aperture.
 18. The method of claim 12 providing the retaining implement having a bottom surface having portions that are curved and extend a distance downwardly parallel to a lengthwise dimension of the aperture to retain the retractor in a desired position.
 19. The method of claim 12 further comprising providing the retaining element having a plurality of separable sections.
 20. The method of claim,19 further comprising providing the separable sections having a plurality of tabs which extend between said sections.
 21. The method of claim 12 further comprising providing a retaining element that is optically transmissive.
 22. A surgical retractor for a coronary bypass procedure comprising; a retaining base having an aperture that exposes an operative site, the base having raised sidewalls; a holder on the retaining base having a slot; and a cord that frictionally attaches to the slot in the holder such that artery tissue can be positioned in the aperture relative to the retaining base with the cord and the holder to occlude flow in the artery.
 23. The surgical retractor of claim 22, wherein the aperture is sized to have a length that ranges from 1 to 3 cm and a width that ranges from 5 to 15 mm.
 24. The surgical retractor of claim 22, having a longitudinal dimension, further comprising raised sidewall elements disposed along the longitudinal dimension of the retractor.
 25. The surgical retractor of claim 24, wherein the raised sidewall elements have a plurality of slots to frictionally grip an end of the cord.
 26. The surgical retractor of claim 22, wherein the cord comprises flexible tape or thread.
 27. The surgical retractor of claim 22, wherein the retaining base comprises a first, a second, a third and a fourth corner, at least one corner has a base having a gradually thinner cross-section to provide a downward slope to allow for fluid drainage during the procedure.
 28. The surgical retractor of claim 22, wherein the retaining base has a bottom surface comprising slots to allow for the placement of the card under or over the retractor to position tissue at the surgical site within the retractor aperture.
 29. The surgical retractor of claim 22, wherein the retaining base has a bottom surface having portions that are curved and extend a distance downwardly parallel to a lengthwise dimension of the aperture to retain the retractor in a desired position.
 30. The surgical retractor of claim 22, wherein the retaining base comprises a plurality of separable sections.
 31. The surgical retractor of claim 30, wherein the separable sections comprise a plurality of tabs which extend between the separable sections.
 32. The surgical retractor of claim 22, wherein the retaining base is optically transmissive.
 33. A method of positioning a coronary artery during bypass surgery comprising the steps of: positioning a retaining base at a surgical site, the retaining base having a first element and a second element which surround an aperture that exposes the coronary artery at the surgical site; connecting the coronary artery at the surgical site to the retaining base with a cord, the cord being frictionally engaged with a slot on the retaining base; grafting a second artery onto the exposed coronary artery positioned in the aperture; and separating the first element and the second element to remove the base from the site.
 34. The method of claim 33 further comprising sizing the aperture to have a length that ranges from 1 to 3 cm and a width that ranges from 5 to 15 mm.
 35. The method of claim 33 further comprising providing the retaining base having a longitudinal dimension comprising raised sidewall elements disposed along the longitudinal dimension.
 36. The method of claim 35 further comprising providing the raised sidewall elements having a plurality of slots to frictionally grip an end of the cord.
 37. The method of claim 33 further comprising providing the retaining base having a first, a second, a third and a fourth corner, at least one corner having a gradually thinner cross-section to provide a downward slope for fluid drainage during a procedure.
 38. The method of claim 33 further comprising providing the retaining base having a bottom surface comprising a plurality of slots to allow for the placement of the cord under or over the retractor to position tissue at the surgical site within the retractor aperture.
 39. The method of claim 33 providing the retaining base having a bottom surface having portions that are curved and extend a distance downwardly parallel to a lengthwise dimension of the aperture to retain the retractor in a desired position.
 40. The method of claim 33 further comprising providing the retaining base having a plurality of separable sections.
 41. The method of claim 40 further comprising providing the separable sections having a plurality of tabs which extend between said sections.
 42. The method of claim 33 further comprising providing a retaining base that is optically transmissive.
 43. A disposable surgical retractor for a coronary bypass procedure comprising; a plastic retaining base having an aperture that exposes an operative site, the aperture extending along a longitudinal axis of the base, the base having a first section separable from a second section; a plurality of holders extending above the retaining base such that a first holder is positioned on a first side of the aperture and a second holder is positioned on a second side of the aperture, each holder having a slot; and an arm attached to the base and extending above the base such that a user can position the base at the operative site with a coronary artery exposed through the aperture.
 44. The surgical retractor of claim 43, wherein the aperture is sized to have a length that ranges from 1 to 3 cm and a width that ranges from 5 to 15 mm.
 45. The surgical retractor of claim 43, having a longitudinal dimension, further comprising raised sidewall elements disposed along the longitudinal dimension of the retractor.
 46. The surgical retractor of claim 45, wherein the raised sidewall elements have a plurality of slots to frictionally grip an end of the cord.
 47. The surgical retractor of claim 46, wherein the connector comprises flexible tape or thread.
 48. The surgical retractor of claim 43, wherein the retaining base comprises a first, a second, a third and a fourth corner, at lease one corner has a base having a gradually thinner cross-section to provide a downward slope to allow for fluid drainage during the procedure.
 49. The surgical retractor of claim 48, further comprising end walls extending widthwise, the end walls in combination with the raised sidewall elements define the first, the second, the third and forth corners.
 50. The surgical retractor of claim 43, wherein the retaining base has a bottom surface comprising a plurality of slots to allow for the placement of the connector under or over the retractor to position tissue at the surgical site within the retractor aperture.
 51. The surgical retractor of claim 43, wherein the retaining base has a bottom surface having portions that are curved and extend a distance downwardly parallel to a lengthwise dimension of the aperture to retain the retractor in a desired position.
 52. The surgical retractor of claim 43, wherein the retaining base comprises a plurality of separable sections each section having a slot that frictionally engages a cord that can extend under the artery.
 53. The surgical retractor of claim 52, wherein the separable sections comprise a plurality of tabs which extend between the separable sections.
 54. The surgical retractor of claim 43, wherein the retaining base is optically transmissive. 